Preparation And Electrochemical Properties Of Ruthenium Oxide-based Composite Electrode Materials For Supercapacitors

As a new electrochemical energy storage device between batteries and conventional capacitors,supercapacitors have attracted a lot of attention in aerospace,energy chemical,electronic devices and other applications because of their long cycle life,short charging and discharging time,high power and energy density and environmental friendliness.The performance depends largely on the electrode materials,the nature of the electrolyte and the voltage window range.Ruthenium dioxide is generally considered to be the best supercapacitor materials due to its high theoretical specific capacitance(1400-2000 F/g),but high production costs and agglomeration effects hinder its marketable application.Therefore,compounding ruthenium oxide with carbon,other transition metal oxides,conducting polymers and other materials to improve the electrochemical properties of the material has become an important development direction for supercapacitor electrode materials.In this paper,ruthenium oxide based composites were prepared as the electrode materials of supercapacitors.The specific research contents are as follows:(1)The amorphous ruthenium oxide/hemp stem activated carbon composites were prepared by liquid phase co-precipitation using tetramethylammonium bicarbonate as the precipitant,and the ruthenium oxide nanoparticles were loaded uniformly and finely on the hemp stem activated carbon.When the content of ruthenium oxide is 40 wt%,the composite electrode material has the highest mass specific capacitance of 436.68 F/g,and the smallest internal resistance of 1.02?.The specific capacitance retention is 91.7%after 1000 cycles with excellent electrochemical performance.(2)Ruthenium-ruthenium oxide/activated carbon composites were prepared by heating in deionized water and ethanol solution respectively,with hemp stem activated carbon as the carrier,RuCl₃-x H₂O as the precursor and tetramethylammonium bicarbonate as the precipitant.The ruthenium oxide/activated carbon electrode material obtained by heating in deionized water has a higher mass specific capacity of 652.79 F/g and the internal resistance of 0.653?.After 1000cycles,the specific capacity remains at 94.3%with good cycle reversibility.(3)Ruthenium oxide/copper oxide composites were prepared at different heating temperatures using RuCl₃-x H₂O and CuCl₂as precursors and tetramethylammonium bicarbonate as the precipitant.The prepared ruthenium oxide/copper oxide composite electrode material prepared at 80?has the optimum electrochemical performance with a mass specific capacitance of 690.23 F/g and the internal resistance of 0.84?.